A 3-YEAR-OLD boy was referred to the pediatric gastroenterology department for evaluation of abdominal pain and vomiting. The patient had a 1-year history of recurrent, acute, episodic abdominal pain that was often associated with vomiting. The episodes occurred infrequently and typically lasted for 48 to 72 hours. There was no nocturnal awakening with abdominal pain or emesis. There was no associated fever, diarrhea, rash, headache, or altered consciousness. The child has maintained growth at the 25th percentile both for height and weight.

Findings from physical examination were normal except for the abdomen. Mild abdominal distension was present with a sense of fullness to palpation, but no mass was felt. There was no tenderness to deep palpation. Results of rectal examination were normal, and a stool sample was guaiac negative. The following laboratory studies were performed and revealed normal results: complete blood cell count, erythrocyte sedimentation rate, amylase, lipase, urinalysis, and urine culture. An abdominal computed tomographic scan was obtained (Figure 1). Surgery was performed, and a large cystic mass was removed (Figure 2).